Ball-mill.



E. GREGORY.

BALL WHLL.

APPLIcImoN FILED Mov, la, ma.

i IA VENTO/6.

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ERNEST. S. GREGORY, OF NACONDA, MONTNA.

- BALL-Mitt.

Specification of Letters Patent.

Patented new ii, taie..

yApplication tlled November 191%. Serial No;` 62,157.

My invention has relation to improve-v ments in ball mills; and itconsistsl in the novel features of construction more fully set` forth inthe specification and pointed out in the claims.

The present improvement is directed to that class of crushing anddisintegrating apparatus wherein 'the material is reduced to particlesof the desired size by meansA of Danish pebbles or steel balls orequivalent freely movable crushing bodies acting by impact and attritionupon the charge temporarily confined within asuitable tumbling barrel,tube, vessel, drum or equivalent container, usually rotated about afixed central axis, the opposite ends or heads of the barrel beingrespectively provided with intake and discharge openings for the,material, as well understood in the art. The material is usually fed tothe barrel. in lllpulp form, a common form of feed device eing a scoopoperating in-a launder or feed-box to which the pulp is supplied fromany available source. The grinding pebbles of course wear and must bereplaced from time to time by adding new pebbles or balls to the mill.It has been the `usual practice to add these by either throwing them inat the' discharge end of the mill., or by putting them in the feed boxto be picked up by the regular scoop feeder. The first method can not beused in many cases on account of the screen with which Amany of thegrinding mills are provided at the discharge end; and at best it is nota very satisfactory method of charging the mill. The, 'other method,that of feeding the balls to be picked up by thescoop is notsatisfactory especially when it is necessary to use feed. scoops oflarge diameter, the pebbles or balls being very apt to become wedgedbetween the moving scoop and the feed-box housing and to either tear thehousing out or else break the scoop.

The object of the present improvement is to overcome theobjectionsinherent in both the old methods, the scheme employed being tointroduce the balls throu h the hollow trunnion through which theeed-scoop discharges into the crushing compartment of thelnill.

y The advantages of the invention will be apparent from a detailed,description thereof in connection with the accompanying drawings, inwhichliigure 1 represents a side elevation of a conventional ball mill,with the pulp feedscoop, ball-feed, and feed-box (or launder) in middlevertical transverse section; Fig. 2 1s an end elevation of one-half ofthe ballfeed or hopper, and of the feed-box, onehalf of the latter beingin vertical section so as to expos/,e the pulp feed-scoop; F ig. 3 is alongitudinal middle section of the replaceable ball-feed tube; and Fig.el is an end" view of the same.

Referring to the drawings` l represents a rotatable cylindricalcontainer, drum or tumbling barrel (or equivalent tubular member)terminating in hollow intake and discharge trunnions and 3,respectively, as well understood in the art, the intake or pulp-feedtrunnion terminating in the feedbox or launder` 4 to which the pulp orcrushed ore m is delivered from any suitable source (notvshown)..Secured to the trunnion 2 within the box 4 is the pulp feed-scoop orfeeder 5 by which (in the rotation of the member l) the pulp is pickedup and automatically discharged through the trunnion into the crushingcompartment C of the member l as well understood in the art.

In the present embodimentof my invention I provide the feed-scoop withan axially disposed ball-feed pipe or tube 6, preferably of cast iron,the same being secured. to the outer face of the feed-scoop through theiiange7 formed on the pipe, the saidv pipe being renewable as the samewears out. The Bange 7 is removed a short distance from4 the outerterminal of thepipe, saidjterminal being supported by the outer wall ofthe box as shown (Fig. l). The'said pipe obviously rotates with thefeed-scoop 5 and with the member or tumbling barrel 1,

i the several members rotating as a unit. yTo

the outer wall of the box l is bolted `or otherwise secured a ballhopper 8 into which the balls or equivalentV movable' crushingl llt)ball-feed pipe (i, through the annular passage a into the trunnion 2whence it is discharged into the crushing compartnient of the mill, the-balls rolling from the hopper 8 through the pipe 6 into the trunnion 2and thence into the mill. Thus it will be `seen that the presentimprovement overcomes all the objections inherent in the old methods offeeding the balls or pebbles to the mill.

In order that the balls may freely gravitate from the hopper 8 into thefeed-tube (l, thel outer end of the latter terminates flush with theinner vertical wall of the hopper as shown in Fig. l. ln .this way theballs encounter no obstruction as they roll into the tube.

l may ofcourse depart from the details of construction here shownwithout in any wise departing from the spirit or nature of theinvention. ln the present structure the trunnion 2 serves as a tubulardischarge for the feed-scoop, butit is obvious that l may provide a.special discharge pipe for the scoop independent of the trunnion withouta departure from the spirit of my invention. Having described myinvention what claim is:

1. The combination with a tumbling-barrel or container rotatable aboutanfixed axis and having a crushing compartment provided respectivelywithV intake and discharge openings for the material disposed aboutsaid` axis, a pulp-feed adapted to be charged from the exterior andprovided with an axial tubular member discharging the material to becrushed into the compartment aforesaid, a stationary holder for thecrushing bodies provided with a. discharge opening, and a ball-feed tubeleading from said opening and discharging into the tubular memberaforesaid.

2. In combination with a tumbling-barrel or container rotatable about afixed axis and having a. crushing compartment provided with a hollowaxial intake trunnion, a pulpbeing flush with the inner wall of thehopper` to permit of ready gravitation of the balls into the tubewithout obstruction.

3. In an appartus ot' the character described, a rotatable pulp-feederprovided with an axial discharge, a detachable ballfeed tube axiallytraversing said pulp-feeder,

.said tube being provided with a securing flange coupled to thepulp-feeder walland removed a suitable distance from the outer end ofthe tube, a stationary feed-box pro` vided with a wall for the supportof said outer end of the tube, and a ball-hopper secured to the feed-boxfor delivering the balls to said tube.

4. ln combination with a tumbling-barrel or container rotatable about afixed axis and having a crushing compartment provided respectively withintake and discharge openings for the material disposed about said axis,a pulp-feed adapted to be charged from the exterior and provided with anaxial tubular member discharging the material to be crushed into' thevcompartment aforesaid, a stationary holder for the crushing bodiesprovided with a discharge opening, and a-ball-feed tube leading fromsaid opening and discharging into the tubular member aforesaid, thedischarge end of the tube being spaced a suitable distance from theinner walls of the tubular member.

In testimony whereof I aiix my signature, in presence of two witnesses.

ERNEST S. GREGORY.

llf'itnesses :4

WALLACE N. TANNE, ALBERT E. WIGGIN.

